International patent publication WO99/14769 discloses an actuator for operating a vacuum switch in a switch gear installation. The actuator is provided with a switch on coil and a switch off coil, and with a permanent magnet for keeping a holding plate locked against a yoke, and against a spring force. Furthermore, a trip device is arranged in the actuator which can counteract the magnet field of the permanent magnet to trip the actuator to an off position using the energy stored in the spring.
An aspect of the present invention provides an improved electromagnetic actuator.